The use of headphones for private listening of an audio device, such as a phone, telegraph or the like, began back as early as the 1900's. The original devices provided very poor sound quality and even less comfort to the user. Such devices have come a long way in the last 20 years with noise-reduction, sound control, feedback control and comfort features as well. However, the prior art has typically taken the “one-size-fits-all” approach to function and comfort and has been unable to offer an in-ear device which is individually customizable for a particular user. The present device addresses this oversight in the prior art by providing an in-ear device which is adjustable to comfortably fit each user, while providing full rich sound quality.
U.S. Patent Publication No. 2009/0028356 A1 (the '356 application), published on Jan. 29, 2009, discloses an in-ear, inflatable, diaphonic member (bubble), for the coupling of sound to the ear, wherein a source of static and active pressure is utilized to inflate the bubble and to keep it inflated. As part of this invention disclosure, a diaphonic valve is described that can convert oscillating sound pressure into static pressure to inflate the bubble in the user's ear. This is accomplished while still passing the sound of the program material (music, voice, etc.) through the valve, into the bubble and thus into the ear, with a minimum of attenuation or distortion. Thus a speaker or acoustical driver of the type used in hearing aids, mp3 player ear buds, or professional in ear monitors may be used to generate static pressures to inflate the diaphonic member (bubble), in addition to playing the program material. The diaphonic valve of the '356 application uses a flat valve design where oscillating sound waves cause oscillations in thin elastic membranes, thus opening and closing ports to harvest the positive pressure, pushing cycles of the speaker and venting in outside air during the negative pressure, pulling cycles of the speaker. Embodiments of the present invention supplement the inventive pumping methods which utilize sound energy to both actively inflate and deflate a diaphonic bubble in a user's ear.
Sound waves generate a sound pressure level and transmit mechanical energy. However, the periodic reversal of the sound pressure, due to the oscillatory nature of the sound waves, makes it difficult to harness sound pressure in the form of the type of static pressure necessary to do PΔV work (where P is an applied pressure and ΔV is a change in volume). An example of PΔV work is the inflation of a balloon. Unfortunately, the sound pressure waves pull as much as they push in every wave cycle, resulting in no net pressure for balloon inflation.
Accordingly, it is desirable to achieve design improvements in the diaphonic valve, which harvests static (analog to DC) pressure from alternating (analog to AC) sound pressure waves. The diaphonic valve may be thought of as a fluid pump which uses sound as its energy source, or alternatively it is analogous to an electronic rectifier that converts alternating electrical current (AC) into direct electrical current (DC). In the present device, the diaphonic valve includes such changes as a reduction in the number of moving parts, increased simplicity of design and manufacture, and greater pressure generating capacity.
A synthetic jet is another featured improvement of the present device. A synthetic jet occurs when a fluid (a liquid or gas) is alternately pushed and pulled through a small orifice. As shown in FIG. 1a, when the fluid is pushed out through the orifice it exits as a narrow, directed jet, which is expelled directly away from the surface containing the orifice. On the pulling stroke, as shown in FIG. 1b, when the fluid is pulled back through the same orifice, the flow field is much different: like fluid going down a drain it enters the orifice mainly from the sides. Even when the amount of fluid pushed and pulled through the orifice on each alternating cycle is the same (and thus there is no net flow of material through the orifice) the asymmetry in the flow fields caused by the push cycle (FIG. 1a) and the pull cycle (FIG. 1b) result in a net flow of fluid away from the face of the surface containing the orifice. At a distance beyond the surface equal to a large number of orifice diameters, the synthetic jet produces a near-continuous jet or motion of fluid, which is difficult to distinguish from a conventional jet such as a hose expelling liquid or gas under a pressure driving force.
Luo and Xia have recently described the design of a “valve-less synthetic-jet-based micro-pump” [Z. Luo and Z. Xia Sensors and Actuators A 122 (2005) 131-140]. A schematic of their device, reproduced from their publication, is shown in FIGS. 2a and 2b. The Luo and Xia pump design was not contemplated for the present, in-ear application, and by its structure could not be of utility in the present invention.
The present invention relates to fluid pumps and the utilization of their output. Also, the present invention addresses and solves numerous problems and provides uncountable improvements in the area of earphone devices and manufacturing methods of the same. Solutions to other problems associated with prior earphone devices, whether the intended use is to be in conjunction with hearing aids, MP3 players, mobile phones, or other similar devices, may be achieved by the present devices.